How Oximeter measures Pulse Rate & Oxygen level in your Blood

A Pulse Oximeter is as small clip like device that measures pulse rate & oxygen level (SPO2) in your blood by non-invasive method .

You should know that a normal resting pulse rate is in between 60 to 100 BPM (beats per minute) and normal oxygen level (SPO2) between 95% to 100% .

As we know that we need oxygen for survival . Oxygen enter our lungs and pass on into the blood . The way oxygen is carried in our blood by means of Hemoglobin . The Hemoglobin (Hb) with oxygen called “ oxy Hb “ and without oxygen called “deoxy Hb” . Oxy Hb and deoxy Hb absorbs infrared & red light differently . Oxy Hb absorb more infrared light and deoxy Hb will absorb more red light .

How it Works :

A pulse oximeter uses a pair of light (infrared & red) of high intensity from LED (Light Emitting Diode)to measure oxygen saturation level in your blood .

The device has a light source and light detector . If a finger is placed between light source and detector , the light has to pass through the finger to reach the detector .

According to law in Physics “The amount of light absorbed is proportional to the concentration of light absorbing substance ” .

As Hemoglobin (Hb) absorbs light . “The amount of light absorbed is proportional to concentration of Hb in blood vessel “ .

As Oximeter detects how much light has been absorbed and how much reaches the detector . In this way oximeter measures the oxygen level in the blood .

In covid-19 pandemic everyone should keep pulse oximeter in his house . This device is small & also not so costly . You may purchase it from any medical store or online store .